MAYO 2.003

                                                MAY 2.003

2.) Drug linked to child deaths is still available in India

Source: http://www.archive.mail-list.com/

Sanjay Kumar New Delhi

A drug known to have serious side effects and which has been banned in parts
of Europe is still available in India, despite reports in the press of
several deaths in the subcontinent among children who had been taking it.

There has been a media furore in India over reports of adverse reactions to
nimesulide, a non-steroidal anti-inflammatory drug, which has been reported
as causing liver toxicity. Although it was approved for use in India in 1994
for painful inflammatory musculoskeletal disorders, it is often used for
pain relief and fever.

Dr Chandra Mohan Gulhati, editor of India's drug information bulletin, the
Monthly Index of Medical Specialities, said that the drug had not been
approved in the United States, parts of Europe, Canada, or Australia and
that last year it was banned in Finland, Spain, and Turkey. "But it
continues to be marketed with impunity in India," he said.

After the media outcry, the drugs controller general of India, Ashwini
Kumar, said on television that the government was appointing a committee to
look into the issue of adverse reactions to the drug.

The deputy drugs controller, Ram Teke, however, told the BMJ that the drug
continues to be available and there was no move to reconsider its use or
approval.

The monthly index puts the national drug turnover to be some 1900 million
rupees (£24.5m; $39.5m; ?37.6m). Besides being available as a single
ingredient, nimesulide is also available in more than 30 other drugs and as
drops for children aged under 1 year. All are unapproved by the drugs
controller and therefore illegal.

"There is no system of monitoring adverse drug reactions in India worth the
name," says Dr Gulhati. The monthly index lists 12 drugs that are banned
globally or whose use is severely restricted or not approved owing to
serious side effects but which are freely available in India. These include
anagen, cerivastatin, droperidol, furazolidone, lynestrenol, nitrofurazone,
phenformin, phenolphthalein, phenylbutazone, piperazine, quiniodochlor.

But even though it has banned the drugs, India's record of implementing any
such ban is phenomenally poor, says Dr Gulhati. He cites the case of
antiallergy drugs astemizole and terfenadine, which hit the headlines last
year. A decision to ban them was announced in June, but the notification was
issued only in October-and the notification said the ban would come into
effect only in August 2003.

'This is the most absurd thing I have ever come across in my life," said Dr
Gulhati. "If the drug is bad and harms people's health, you ban it with
immediate effect." Such decisions are taken only to help the manufacturers,
he added. He lists commercial interests of the pharmaceutical lobby,
corruption, and total lack of accountability and transparency as the key
ailments affecting the drug regulatory mechanism in India.

Adverse media reaction has resulted in two companies reportedly announcing
cuts in the manufacture of nimesulide.

Ajay Kumar Handa, president of marketing for the Bombay based Centaur
Pharmaceutical, said: "We are no longer supplying nimesulide suspension." He
said that Mr Handa says their decision follows reports of paediatric
hepatotoxicity and added: "As far as I understand there is no problem with
adult doses of nimesulide." Some other manufactureres too have withdrawn the
product, Mr Handa confirmed.

A public interest petition filed in December 2002 in Delhi High Court by the
Social Jurist legal group has challenged the availability of nimesulide and
other banned drugs in India.

3.) The ban on Nimesulide abroad causes panic in India
Source: http://www.the-week.com/

K. Sunil Thomas with Quaied Najmi and Ambica P. Prabhan

Anger and amazement laced the voice of Dr Vasant Khatau. "Should our children be treated as guinea pigs for earning money?" asked the Mumbai pediatrician. The question would have upped the panic of parents who learnt last week that Nimesulide, a drug often prescribed to bring down high fever in children, was found to cause serious liver complications in some patients during tests in Europe. "Our customers, especially parents buying Nimesulide for their kids, are confused and frightened," said Dinesh Sukhija, a chemist near Delhi's Ram Manohar Lohia Hospital.

Is it safe? A chemist in New Delhi displays the various Nimesulide products

Drug-related controversies are not new in a country which has for long been considered the dumping ground for sub-standard medicines. Nimesulide is the new entrant in this arena with 13 deaths reported from all over the world. A non-steroid anti-inflammatory drug, its popularity stems from its effectiveness in bringing down high fever. Now, however, several European countries have withdrawn it after it was found to cause serious liver complications, especially in children. Even its innovator, Boehringer, withdrew it earlier this year from Spain and Finland. Interestingly, the drug was never licensed in the US, Canada, Australia and Britain.

Panic was triggered in Indian homes after the local media reported the warnings issued in Europe over the dangerous instances of liver toxicity caused by the drug. The drug first appeared in the country in the late eighties as the brand 'Rimulide' from a Bangalore-based pharma company. There are at least 20 major pharma companies in India manufacturing the drug under different brand names and it accounts for a turnover of Rs 200 crore.

As the controversy broke, the medical fraternity remained divided on the issue of side effects. According to Dr S. Malhotra, who runs a polyclinic in south Delhi, "The side effects of acidity and heartburn are minor and it is considered safe for asthma patients, unlike other pain killers." However, Dr Khatau wanted Nimesulide in the syrup and dispersible tablet forms, widely prescribed for children and infants, to be immediately banned. Some of the doctors believed that a quantity of five milligrams and above had the potential to cause serious liver and kidney problems; overdose can even result in total kidney failure. What is coming out, said Dr P.K. Rajiv, head of newborn services at the Amrita Institute of Medical Sciences and Research Centre in Kochi, is "just the tip of the iceberg". He was sure that Nimesulide-related deaths were taking place in the country though no one was ready to come out with the figures yet. "We wouldn't have had to wait for the US to ban it if proper surveillance had been done in the country," he added.

Doctors have for long been baffled by an increase in liver-related problems, especially in the elderly. In most cases it was found that the patients had been prescribed a high dosage of Nimesulide for a long period. Sadly, there is no proper monitoring in India to track the possible side effects of a new drug. As Dr Philip Augustine of Kochi put it, "If we were to go by available information alone, we would not be able to use most of the drugs which come out."

Pharma companies sponsor clinical research into the safety and efficacy of their drugs-and it is common knowledge that the results, if negative, are either not published, or glossed over. "We call them anecdotal reports," said Dr H.P.S. Sachdev, president-elect of the Indian Academy of Pediatrics. "A lot of factors have to be taken into account while evaluating a drug," said T.R. Gopalakrishnan, assistant secretary-general of the Indian Drug Manufacturers Association.

What is needed now are detailed clinical trials to determine whether it was a combination of factors that led to liver toxicity in users of Nimesulide or whether the drug itself is at fault. But even as the Drug Controller of India decided to review the case and experts suggested that the panic was probably exaggerated, parents could do little but worry endlessly.

3.) Use of nimesulide in Indian children must be stopped.

Source: http://www.bmj.com

EDITORThe continuing use of nimesulide for Indian children is shocking.1 Numerous studies have established the life threatening hepatotoxic effects of nimesulide. 2 3 Nimesulide is not used in the United States, and many European countries have also banned the drug because of its unacceptable rate of serious adverse reactions.
Although some studies have indicated that nimesulide may be chosen for osteoarthritis in selected patients with associated gastric problems, other non-steroidal anti-inflammatory drugs such as acetaminophen (paracetamol) are far better choices as antipyretics or analgesics, especially for children.4 No rationale exists for selecting nimesulide as the first drug of choice for fever or pain. Published studies from India indicate rampant abuse of nimesulide.5 At least 12 paediatric preparations of nimesulide are available in India, which affirms the widespread use of the drug in children.5
Hardly any dependable post-marketing surveillance for adverse drug reactions is undertaken in India. Moreover, unlike in the West, Indian doctors are not under any real supervision and therefore do not necessarily keep up with the rapidly changing information about adverse effects.5 Patients receiving nimesulide should be closely monitored for evolving hepatic failure. Indian patients may not follow necessary guidelines, for simple economic reasons. Even if the Indian drug control agencies are reluctant to impose a total ban on nimesulide, they should immediately forbid its use for treatment of fever or pain.
A plethora of scientific data show that nimesulide should not be used as the primary mode of treatment as an antipyretic or analgesic, especially in children, for whom much better and safer choices are available. It will be unfortunate if the Indian government waits for another "committee" report before stopping the use of nimesulide, even for the treatment of pain or fever, and lets more innocent patients suffer needlessly.

Kunal Saha, assistant professor. 
Department of Pediatrics and Molecular Virology, Immunology and Medical Genetics, Children's Hospital and Ohio State University Medical Center, 700 Children's Drive, Columbus, OH 43205, USA [email protected]


1. Kumar S. Drug linked to child death is still available in India. BMJ 2003; 326: 70[Free Full Text]. (11 January.)
2. Ferreio S, Vivas F, Jorquera AB, Dom'uez J, Herrera A, Fern'ez MJ, et al. Nimesulide-induced hepatotoxicity. Case report and bibliography review. Gastroenterol Hepatol 2000; 23: 428-430[Medline].
3. Merlani G, Fox M, Oehen HP, Cathomas G, Renner EL, Fattinger K, et al. Fatal hepatoxicity secondary to nimesulide. Eur J Clin Pharmacol 2001; 57: 321-326[CrossRef][ISI][Medline].
4. Litalien C, Jacqz-Aigrain E. Risks and benefits of nonsteroidal anti-inflammatory drugs in children: a comparison with paracetamol. Paediatr Drugs 2001; 3: 817-858[Medline].
5. Malhotra S, Pandhi P. Analgesics for pediatric use. Indian J Pediatr 2000; 67: 589-590[Medline


4.) Safety and tolerability of the dual 5alpha-reductase inhibitor dutasteride in the treatment of benign prostatic hyperplasia.
Eur Urol. 2003 Jul;44(1):82-8. Related Articles, Links
Andriole GL, Kirby R.

Division of Urologic Surgery, Washington University School of Medicine, 4960 Children's Place, Campus Box 8242, 63110, St. Louis, MO, USA

OBJECTIVE: The objective of this paper is to examine safety and tolerability data from a number of recently completed clinical trials with the novel, dual 5alpha-reductase inhibitor, dutasteride.METHODS: Intent-to-treat analyses were conducted on data for dutasteride 0.5mg/day for drug-related adverse events, clinical laboratory test results, and prostate-specific antigen (PSA) levels derived from four large, randomised, double-blind clinical trials (n=5655). Further data were derived from a randomised, double-blind combination study of dutasteride 0.5mg/day and tamsulosin 0.4mg/day (n=327), and several safety studies conducted in healthy volunteers.RESULTS: Data from two-year blinded clinical studies demonstrate that dutasteride is well tolerated, with a profile comparable with that of placebo. The exception is a modestly elevated incidence of impotence, decreased libido, ejaculation disorders, and gynaecomastia. Clinical laboratory test abnormalities were reported by <1% of patients treated with dutasteride, and abnormal values occurred with similar frequency versus placebo-treated patients. In a healthy volunteer study, when dutasteride was administered daily for 1 year, it did not significantly affect bone metabolism markers, bone mineral density or lipid profiles. Dutasteride reduced total serum PSA concentrations by approximately 50% following 6, 12, and 24 months of treatment but had no effect on free-to-total PSA levels. The safety profile of dutasteride did not differ from that of finasteride in a large, parallel-group, comparator trial. Additionally, when dutasteride was used in combination with an alpha(1)-blocker, the drug-related adverse event profiles were as would be expected for the individual agents.CONCLUSIONS: Considered together, these data demonstrate dutasteride to be well-tolerated.


5.) Efficacy and safety of a dual inhibitor of 5-alpha-reductase types 1 and 2 (dutasteride) in men with benign prostatic hyperplasia.
Urology. 2002 Sep;60(3):434-41. Related Articles, Links

Roehrborn CG, Boyle P, Nickel JC, Hoefner K, Andriole G; ARIA3001 ARIA3002 and ARIA3003 Study Investigators.

Department of Urology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9110, USA.

OBJECTIVES: To study the efficacy and safety of dutasteride, a dual inhibitor of the 5-alpha-reductase isoenzymes types I and II. METHODS: A total of 4325 men (2951 completed) with clinical benign prostatic hyperplasia, moderate to severe symptoms (American Urological Association-Symptom Index score of 12 points or greater), a peak flow rate of 15 mL/s or less, a prostate volume of 30 cm3 or greater (as measured by transrectal ultrasonography), and a serum prostate-specific antigen level of 1.5 to 10.0 ng/mL (inclusive) were enrolled into three identical clinical trials and randomized to 0.5 mg dutasteride daily or placebo. After a 1-month, single-blind, placebo lead-in, patients were followed up for 24 months in a double-blind trial with multiple interval assessments. RESULTS: At 24 months, serum dihydrotestosterone was reduced from baseline by a mean of 90.2% (median -93.7%; P <0.001), and the total prostate and transition zone volumes were reduced by a mean of 25.7% and 20.4%, respectively (P <0.001). The symptom score was improved by as early as 3 months, with pooled significance from 6 months onward (P <0.001) and a reduction of 4.5 points (21.4%) at 24 months (P <0.001). The maximal flow rate improved significantly from 1 month (P <0.01), with an increase of 2.2 mL/s reported at 24 months (P <0.001). Hence, the risk reduction of acute urinary retention was 57% and the risk reduction of benign prostatic hyperplasia-related surgical intervention was 48% compared with placebo. The drug was well tolerated. CONCLUSIONS: Dutasteride is a potent inhibitor of dihydrotestosterone production that is safe and effective in terms of the reduction of prostate volume and symptoms, flow rate improvement, and the reduction of the risk of acute urinary retention and surgery during a 24-month study period.


6.) Levitra ./ a new oral treatment for erectile dysfunction
Source: http://www.healthexpress.co.uk/

What is Levitra?

Levitra is a new oral treatment for erectile dysfunction (impotence) available in the UK. This factsheet provides basic information on Levitra.


Levitra (vardenafil) belongs to a group of medicines called PDE5 inhibitors. It is a round shaped orange tablet with strengths of 5mg, 10mg or 20mg. It is an oral tablet, which is swallowed. It is not an aphrodisiac and does not increase sexual desire. For Levitra to be effective, sexual stimulation is required.

You can obtain treatment for impotence using Levitra at www.healthexpress.co.uk

How does Levitra work?
Levitra works by helping to relax the blood vessels in the penis, allowing blood to flow into the penis causing an erection. Levitra will not give a man an erection spontaneously, it will only help a man to get an erection if he is sexually stimulated.

How do you take Levitra?
Levitra is available in three strengths 5mg, 10mg and 20mg. The initial dose is selected by the doctor who will assess the most appropriate dose for each patient based on a consultation.

Levitra normally works within 25-60 minutes, although some men will achieve an erection within 15 minutes. Within a 5 hour period after taking the tablet an erection should occur in response to sexual stimulation.

The action of Levitra is not generally affected by eating before taking the treatment (except where the meal has a fat content of 57% or greater) or by drinking alcohol, so men can eat or drink as they would normally before taking Levitra.

It is recommended that only one dose of Levitra is taken in a 24 hour period.


What side effects may be associated with Levitra?
The manufacturers have tested the drug in over 3,750 men in worldwide clinical trials. When taken at the recommended dose, side effects are mild and transient. The most common side effects are headache and facial flushing.

Who cannot take Levitra?
Patients who are taking any medicines containing nitrates. These are commonly prescribed for the relief of angina (chest pain). Levitra, in combination with nitrates, can lower blood pressure significantly leading to untoward effects. Patients should inform their doctor if they are taking any of these medicines or should ask if they are uncertain.

Patients with the following:

Known hypersensitivity to any component of the drug Levitra;

Men with cardiac disease of a severity where sex is inadvisable;

Recent stroke, heart attack or low blood pressure;

Unstable angina or angina occurring during sexual intercourse;

Aged over 75 years and taking ritonavir, indinavir, ketoconazole or itraconazole (oral form)

Levitra should not be taken with other erectile dysfunction treatments.

You can obtain treatment for impotence using Levitra at www.healthexpress.co.uk

What conditions may prevent a man using Levitra?
Levitra should be used with caution in patients with:

An abnormally formed penis.

Diseases that might result in prolonged erections e.g. Sickle cell anaemia, multiple myeloma, or leukaemia.

A history of postural hypotension.

Severe kidney or liver disease

Can women take Levitra?
Levitra should not be taken by women as it is not licensed and its safety in women has not been tested.

What happens if I increase the dose?
An increase in dose should always occur under close medical supervision. Clinical trials have shown that increasing the dose beyond the maximum recommended dose of 20mg simply increases the side effects and not the efficacy.

You can obtain treatment for impotence using Levitra at www.healthexpress.co.uk

Can I drive while taking Levitra?
As dizziness has been reported in clinical trials of Levitra, patients should be aware of how they react to the drug before they drive.

Will it work for everyone?
If Levitra does not help you to get an erection, or your erection does not last long enough for you to complete your chosen sexual activity you should tell your doctor, who will be able to advise you as to whether a dose increase is necessary to reach the desired effect.

Your doctor can also advise you on other possible treatment options.

You can obtain treatment for impotence using Levitra at www.healthexpress.co.uk


7.) Saw palmetto for prostate disorders.
Am Fam Physician. 2003 Mar 15;67(6):1281-3.
Gordon AE, Shaughnessy AF.

Harrisburg Family Practice Residency Harrisburg, Pennsylvania 17110-2098, USA. [email protected]

Saw palmetto is an herbal product used in the treatment of symptoms related to benign prostatic hyperplasia. The active component is found in the fruit of the American dwarf palm tree. Studies have demonstrated the effectiveness of saw palmetto in reducing symptoms associated with benign prostatic hyperplasia. Saw palmetto appears to have efficacy similar to that of medications like finasteride, but it is better tolerated and less expensive. There are no known drug interactions with saw palmetto, and reported side effects are minor and rare. No data on its long-term usage are available. The herbal product also has been used to treat chronic prostatitis, but currently there is no evidence of its efficacy.

8.)Long-term clinical and biologic effects of the lipidosterolic extract of Serenoa repens in patients with symptomatic benign prostatic hyperplasia.
Adv Ther. 2002 Nov-Dec;19(6):297-306.

Pytel YA, Vinarov A, Lopatkin N, Sivkov A, Gorilovsky L, Raynaud JP.

Scientific Research Institute of Urology, Moscow, Russia.

Permixon, the lipidosterolic extract of Serenoa repens, is widely used for the treatment of symptoms associated with benign prostatic hyperplasia (BPH). This open study assessed the efficacy and tolerability of Permixon 160 mg twice daily administered for 2 years. One hundred fifty-five men with clinically diagnosed BPH and complaints of prostatic symptoms were enrolled in the study. At 6, 12, 18, and 24 months, the International Prostate Symptom Score (I-PSS), quality of life, and sexual function score were recorded, and urodynamics and biologic values were measured. Adverse events were recorded every 3 months. I-PSS and quality of life improved significantly from baseline at each evaluation time point. At the end of the study and at each evaluation, maximum urinary flow also improved significantly. Prostate size decreased. Sexual function remained stable during the first year of treatment and significantly improved (P = .001) during the second year. Prostate-specific antigen was not affected, and no changes in plasma hormone levels were observed. Nine patients reported 10 adverse events, none related to treatment. Improvements in efficacy parameters began at 6 months and were maintained up to 24 months. These data demonstrate the long-term efficacy and tolerability of Permixon and support its use as a first-line medical therapy for uncomplicated symptomatic BPH.

9.) Oh, NO! Not Tongue Piercing!!!
Source: http://www.floss.com/

by Nanette Feuling

I was finally asked to research the inevitable. I knew at some point I would get an assignment that shows my age. This is the one, people, this is the one! For the life of me, I can’t imagine wanting your tongue pierced, but then I also did not want my ears done. I have only had them pierced for about 20 years, now, but it took my teenage daughter’s power of persuasion at least six months before she could drag me into her world back before tongues were even “in.”

I think I have been able to get the “scoop” on the tongue thing. All sources, except testimonials and advertisements, concur that it’s thumbs down. Now you already knew that, so let’s cut to the chase and lay out the facts. Then you can go ahead and do what you knew you really shouldn’t do even before you read this, even when you ultimately become more aware than ever of the dangers – you can go right ahead even though you may be literally scared to death!


The Procedure
Tongue piercing is a process whereby the tongue is penetrated with a medical needle encased in a plastic cannula or sheath. When the needle is removed, the cannula is left in place. A stainless steel barbell (jewelry) is then placed through the cannula lumen or hole; subsequently, the cannula is removed leaving the barbell pierced through the tongue.

The Risks
Infection
Two infection risks exist: (1) Systemic and (2) Localized

Systemic Infection
HIV virus and Hepatitis are two examples of systemic infection risks if a sterile environment is not maintained during a piercing procedure. Autoclave sterilization of instruments and equipment must be used for the procedure to avoid these systemic risks and remains perhaps the number one requirement for any “Piercer.” Toxic shock is a third serious systemic problem that has resulted from piercing gone awry.


Localized Infection
Slight swelling of the tongue and a pale yellowish discharge consisting of lymph and plasma around the wound site are common localized occurrences with piercing. While the tongue is notorious for its ability to swell when injured, even to the point of airway obstruction and resultant breathing difficulties, no less dangerous is localized infection of the wound that can spread despite efforts with antibacterial care. Although these severe consequences are not usual or normal occurrences, they are formidable risks. It is absolutely necessary to call your dentist immediately if any persistent or unusual swelling occurs or if any unexpected infection becomes apparent. However, when the procedure heals routinely, the patient maintains cleanliness at the site by means of careful brushing with a soft brush, saltwater rinses, and topical antibacterial mouthwash. Tech 2000 and Biotene are products that contain no alcohol and, therefore, do not irritate or sting. Gly-Oxide, an antiseptic oral cleanser, may be used to promote healing, as well.

Allergic reactions to inferior-grade metals used as jewelry objects are also a common source of infection. Stainless steel, titanium, and gold are appropriate metal choices.

Oral Consequences, Accidents, and Abrasions
Stories of “barbells” being swallowed during the night that lodge in the trachea, swollen tongues to the point of tracheostomy, stories of broken teeth, as well as excessive bleeding during piercing from veins in the tongue - horror stories, literally, abound. More likely, therefore ultimately more threatening, are the tiny tooth fractures that can begin to show on x-rays after extended intermittent biting on those metal objects used for jewelry. One young aficionado reports, “And they say tongue rings chip your teeth. Well I have bit mine a lot. I mean I bite it everyday, and I haven't chipped a tooth.” That young man hasn’t had his yearly dental x-rays since the procedure, either. Small fractures can completely undermine a tooth and are a common result and a realistic consequence of tongue piercing.

Post-procedure, patients routinely experience temporary excessive salivation, pain, speech impediment, and irritation from foods, especially salty foods. They are advised to use ice to reduce symptoms and to maintain a liquid diet for a short duration. Because the tongue is a muscle, unlike the earlobe, additional more serious consequences are a reality, although they occur infrequently. These risks include scarring, permanent damage to veins and nerves, deep cyst formation, as well as development of neuromas that are defined as overgrowth of nerve tissue. These complications can produce permanent loss of taste, sensation, and tongue mobility. The tongue is infused with a vascular network; therefore, piercing causes considerable bleeding. When a blood clot forms at the wound site, there is also the remote but distinct possibility that a small piece could break away and flow through the blood stream to lodge in the brain causing a stroke.


Bad Breath
Any body orifice that can harbor bacteria is also a potential cause of bad breath, elevating oral hygiene to a position of even more than normal importance after piercing. Dental offices routinely see plaque-coated barbells from inconsistent and careless hygiene. If this piercing fashion statement is truly meant to be appealing, it comes with the responsibility to be ultra-conscientious. Frankly, when I see “science” as a part of the word “conscience” – literally, con (with) science - and “conscientious,” I know why I said, “Oh, NO! Not tongue piercing!” But then, I also know what peer pressure is all about. It took my teenage daughter six months, remember, to get me to pierce my ears. And then, in the grand finale, as a final result, I ended up betraying my conscience!* It was not a move my better judgment dictated, but ear piercing also carried minor risks compared with tongue piercing.


 I am glad that when I chose to betray my conscience - that I had all the facts about what I was going to do. It made the “odds” better to assure that I would get the best possible results with the least probable chance for casualty. There is a math course that is the study of “odds,” called “Permutations and Combinations.” Playing the odds in one’s favor is using math as a backup when you choose to go against your conscience and to assume a risk. As with science, it requires proper compilation of reliable data under the circumstances to give you your best bet.

10.) Hepatitis C
Source: http://www.sdpt.net/hepatitisc.htm

Prevalencia e incidencia
El escIarecimiento del genoma del virus de la hepatitis C en 1989 implicó que se adquiriera conciencia de que este virus es un grave problema de salud en todo el mundo, además de saberse que la infección por el virus de la hepatitis C (VHC) es una de las causa más frecuentes de hepatopatía crónica. El 40% de las personas ignoran su estado y se calcula que en la Argentina hay alrededor de 600.000 casos. En cuanto a los dadores de sangre voluntarios sanos, por cada 100 hay uno que padece la enfermedad y no lo sabe.

Si bien no hay datos precisos el mal se desarrolla con más frecuencia en Capital Federal y el Conurbano Bonaerense.

En los Estados Unidos el 1 % de la población es portadora del VHC un estimado de 2,7 millones de personas, mientras que en todo el mundo hay cerca de 170 millones de personas portadoras del VHC, según la OMS.

De no abaratarse la medicación, para el año 2008 la tasa de incidencia de la enfermedad aumentará en un 500%. El tratamiento hoy cuesta entre $ 2.000 a $ 4.000, por mes.

El virus de la hepatitis C (un RNA virus) posee muy poco en común con los virus de las hepatitis A y B, mejor conocidos. Es un miembro de la familia Flaviviridae, que comprende virus como los de la fiebre amarilla y el dengue. La partícula viral consta de una cubierta derivada de las membranas del huésped, en la cual se insertan las glucoproteinas E1 y E2 codificadas por el virus, que rodea a la nucleocápside, y un genoma ARN monocatenario de sentido positivo y una longitud aproximada de 9.500 nucleótidos.

El virus de la hepatitis C se ha clasificado en 6 genotipos importantes basados en los análisis filogenéticos. Los 6 genotipos principales se designan por números:

1,2,3,4,5 y 6. Todavía no se pudo cultivar en el laboratorio.

Formas de transmisión
El 40% de las causas de contagio se desconoce. La hepatitis C se transmite por vía parenteral. Antes de 1992 cuando aún no se usaban las pruebas de detección en donantes de sangre y otros exámenes la transfusión de sangre o productos derivados del plasma se acompañaba de un Importante riesgo de transmisión de la hepatitis C. Otros factores de riesgo de potenciales contagios son: El uso de cocaina intranasal, los tatuajes, los piercing corporales, los pinchazos accidentales con agujas, y el compartir utensilios del hogar como corta uñas, hojas de afeitar y cepillos de dientes.

También ha habido descripciones de casos de transmisión de hepatitis C entre pacientes sometidos a colonóscopia con un colonoscopio inadecuadamente desinfectado; entre dos miembros de una familia que emprendieron una pelea a puñetazos en la que corrió sangre; luego de usar filtros hemodialisadores en varios pacientes y durante cirugías cardiotorácicas.

Los pinchazos accidentales con agujas que sufren los trabajadores sanitarios pueden transmitir el virus. La frecuencia de esta vía de contagio es inferior a la observada con la hepatitis B, pero superior a la del VIH. Después de un pinchazo, la gammaglobulina o la globulina inmune contra hepatitis B carecen de valor en la prevención de la infección por hepatitis C. La expectación vigilante es una estrategia importante para determinar si se va a desarrollar o no la enfermedad. Si es posible, resulta adecuado revisar la carga viral de hepatitis C en el paciente, con el fin de evaluar el riesgo de transmisión. El peligro de contagio de hepatitis C es despreciable cuando el paciente carece de ARN de hepatitis C detectable. Sin embargo, si no se dispone del paciente de origen para realizarle las pruebas o la prueba de ARN de VHC es positiva en él, el receptor del pinchazo debe ser sometido periódicamente a pruebas de VHC, además de recibir tratamiento si resulta positivo para ARN de VHC.

La transmisión sexual de la hepatitis C sigue siendo objeto de controversia y probablemente supone menos del 5% de los casos. Los factores dé riesgo son la promiscuidad sexual, las relaciones con prostitutas, el intercambio sexual rectal y las relaciones sexuales traumáticas. Estudios en parejas casadas indicaron un riesgo mayor de transmisión al cónyuge a medida que se prolonga la duración del matrimonio. Se ignora si este riesgo es secundario a transmisión sexual y falta determinar el papel potencial de compartir los enseres del hogar, las hojas de afeitar y los cepillos de dientes.

La transmisión perinatal de la hepatitis C se produce aproximadamente en el 3% al 5% de los lactantes nacidos de madres infectadas por VHC. Esta vía de contagio se asocia a dos factores de riesgo independientes: elevada carga viral en el momento del parto y tener una madre VIH positiva.

Investigadores italianos describieron recientemente una disminución del riesgo de transmisión perinatal de hepatitis C en el parto por cesárea comparado con el vaginal. El riesgo de transmisión perinatal de la hepatitis C en una mujer VIH positiva se estima en el 15% al 35%. Los niños nacidos de madres infectadas por hepatitis C pueden tener inicialmente anticuerpos positivos contra hepatitis por transferencia pasiva a través de la placenta. Este anticuerpo puede estar presente durante todo el primer año de vida, para luego desaparecer. Por lo tanto, para determinar si existe infección por hepatitis C en el recién nacido, es necesario demostrar la Positividad del ARN de VHC en el suero. La lactancia natural por madres con hepatitis C parece segura, y no se han descrito casos de transmisión del virus a los recién nacidos.

Otros Factores
Otros grupos de alto riesgo de infección por hepatitis C comprenden las personas que recibieron concentrados de factores de coagulación antes de 1987, personas sometidas a hemodiálisis, hemofílicos y pacientes receptores de trasplante de órgano sólido o de médula ósea antes de 1992. La contaminación de las membranas de ultrafiltración puede explicar la elevada tasa de infección por hepatitis C observada en las unidades de diálisis.

Evolución Natural de la Hepatitis C
La historia natural precisa de la hepatitis C sigue siendo desconocida debido a la falta de datos prospectivos, la imposibilidad de determinar el momento de inicio de la enfermedad y a las influencias variables de los numerosos cofactores que conducen a su progresión. Lo que sí se determinó es que un subgrupo de pacientes con hepatitis C progresará a la cirrosis y a las complicaciones que la acompañan.

El sello de la infección por hepatitis C es la cronicidad: entre el 15% y el 30% de los pacientes expuestos a VHC se recuperan espontáneamente, mientras que del 70% a 85% restante desarrollan infección crónica. La mayoría de los pacientes con infección crónica por hepatitis C parecen tener una enfermedad histológicamente leve a moderada. Aunque en la hepatitis C es rara la infección fulminante, se han descrito casos.

Varios estudios trataron de determinar la velocidad de progresión histológica en la enfermedad adquirida por transfusión. Tong y colaboradores encontraron un intervalo medio de 20 años desde el momento de la infección hasta el desarrollo de la cirrosis, y un intervalo medio de 28,3 años desde el momento del diagnóstico y el desarrollo del carcinoma hepatocelular. (CHC)

Varios factores parecen influir sobre la velocidad de progresión de la hepatitis C a cirrosis. Estos factores comprenden el consumo de alcohol, la edad en el momento de la exposición, el sexo, y la coinfección con hepatitis B o con VIH.

La ingestión de alcohol y la infección crónica por hepatitis C actúan de forma sinérgica, acelerando la progresión de la hepatopatía. Si el consumo mantenido de alcohol es superior a 40 gramos día existe un aumento del riesgo de cirrosis y de hepatopatía descompensada. Otros efectos del empleo concomitante de alcohol en el contexto de la hepatitis C son los niveles más elevados de transaminasas, cargas de virus de hepatitis C mayores de número de cuasiespecies de hepatitis C. Los valores negativos se reducen si se abandona el hábito de consumir alcohol. A partir de los cuarenta años de edad, la progresión se acelera tal vez por fallas del sistema inmunológico.

Por otra parte, la coinfección de hepatitis C y VIH parece llevar a una progresión rápida de la hepatopatía. La evolución hacia la cirrosis o la falla hepática puede ocurrir entre 10 y 15 años más tarde del momento de infección con el VHC. La velocidad de esta progresión duplica aproximadamente a la que ocurre con la infección por hepatitis C aislada. En la actualidad, la hepatitis C y la hepatopatía relacionada con ella son la primera causa de muerte no asociada a Sida en pacientes con VIH.


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DATA-MEDICOS/DERMAGIC-EXPRESS /MAY JOURNAL 2.003/ DR. JOSE LAPENTA R. 
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